Abstract:
Milk wished-for human consumption has to be free from potentially harmful bacteria. A crosssectional
study was conducted from November 2017 to June 2018 to assess milk handling
practice among dairy farms, to estimating the prevalence of S. aureus in raw milk and swab,
to assess associated risk factor of S. aureus and S.aureus load in raw milk, and the
antimicrobial susceptibility profile of S.aureus isolates in selected dairy farms of Mukaturi
and Sululta Town, Oromia Regional State, Ethiopia. The possible risk factors for S.aureus
contaminations in milk were evaluated face to face interviewed 77 respondents through a
structured questionnaire randomly base on their intimate to the farm. A total of 247 samples
(183 raw milk from lactating cow by simple random sampling technique collected from
purposively selected dairy farms and depending on number of worker, frequencies of farm
visit and material used 64 swab samples) were examined using standard microbiological
techniques. The antimicrobial susceptibility profiles of the isolates were also investigated
using disc diffusion method. In the study area with regard to milk handling, 72.1% of
respondents (milk consumers) used plastic containers for milk handling meanwhile only
37.2% kept milk in refrigeration before consumption and 60.5% of milk users had habit of raw
milk consumption. From milking personnel 47.1% store milk at room temperature temporarily
between 6-12 hours till transport to collection center with no means of cooling aid. Overall,
16.6% (n= 41) of the samples were positive for S. aureus. The prevalence of S. aureus was
15.3% from udder milk and 25%, 20% and 10% from milkers’ hand, milking bucket and
drying towel swab respectively. The prevalence of S.aureus in milk were statistically
significant variation with respect to age (p=0.000), parity (P= 0.000) and regarding with
drainage condition of milking area (P=0.035), farming area (P=0.035) and management
system (P=0.035). The isolates were found to be resistant to penicillin G (97.6%), and
Amoxicillin (43.9%). According to this study, 12(42.9%) raw milk samples had >104cfu/ml
S.aureus count, which is above the recommended level for human consumption. The study
revealed a prevalence of antimicrobial resistant S. aureus from raw milk cow and swabs, poor
milk handling practices, raw milk consumption behavior in study area. Proper handling and
hygiene decrease milk contamination by S.aureus and make it safe for human consumption.
